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A131712
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Period 4: repeat [1, 3, 7, 9].
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3
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1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1, 3, 7, 9, 1
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OFFSET
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0,2
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COMMENTS
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LINKS
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FORMULA
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G.f.: (1+3*x+7*x^2+9*x^3)/((1-x)*(x+1)*(1+x^2)). - R. J. Mathar, Nov 14 2007
a(n) = a(n-4) for n>3.
a(n) = 5 - 3*cos(n*Pi/2) - cos(n*Pi) - 3*sin(n*Pi/2) - I*sin(n*Pi). (End)
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MAPLE
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MATHEMATICA
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PROG
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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